5. Tubeaxial Fans: The Workhorses of Industrial Ducted Ventilation The Tubeaxial fan represents a foundational and robust category of axial cooling fans, specifically designed for applications involving ducted airflow[13]. Structurally, a Tubeaxial fan consists of a propeller-style impeller mounted within a tight, cylindrical housing, or 'tube'[13]. The housing performs a critical function by minimizing the clearance between the blade tips and the casing wall, a design feature essential for preventing air recirculation and maintaining the desired pressure differential[13]. This tight enclosure allows the fan to overcome the moderate system resistance presented by ductwork, filters, or coils, a capability that distinguishes it from the simple, non-ducted propeller fan[13]. Tubeaxial afs fans are typically used in mid-pressure applications, such as exhaust ventilation for heat, smoke, and fumes in industrial workshops, factories, and warehouses[13][18].